Telephone system.



PATENTED SEPT. 24, 1907.

H. 'P. GLAUSEN. TELEPHONE SYSTEM. APPLICATION FILED 00125, 1-901.

names.

UNITED sTA rns PATENT OFFICE.

HEN RY P. CLAUSEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERICAN ELECTRICTELEPHONE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

TELEPHONE SYSTEM.

Specification of Letters Patent Patented Sept. 24, 1907.

Application filed 0ctober2 5, 1901. Serial No. 7 9.900.

.of the United States of America, and a resident of Chicago, county ofCook, and State of Illinois, have invented certain new and usefulImprovements in Telephone Systems, of which the following is aspecification.

My invention relates to telephone systems in general; but moreparticularly to systems of the central energy type, and especially tosystems in which complete me-r tallic circuits are provided for talkingand ringing the bellsat the substations.

Generally stated, the object of my invention is to provide certaindetails and features of improvement which will tend to increase thegeneral efiiciency of a telephone system of this character.

Certain'special objectsare to provide a'circuit ar rangement which willpermit the central operator to answer a call without producingobjectionable or disagreeable sounds in thereceiver at the substation,and which will" permit the signaling current to hold the calling signalin operation until the call is answered, it being also an object of theinvention'to provide a circuit arrangement of such character as toenable the signaling battery to operate or light a calling signal lampthrough a short local circuit of comparatively low and unvaryingresistance.

Other special objects of my invention are to provide an improvedconstruction and arrangement by which the relay which connects thenormally disconnected jack-with'the' subscribers line is energized overa ,cir

which is absolutely independent of the ground at the subscribersstations, whereby the subscribers in signaling for a disconnection donot use the ground he tween the substations and the'exchange or centralstation; to provide an improved construction and arrangement whereby itwill not be' necessary to use a series of normally open contacts in thenormally dis-' connected jacks for closingthe energizing 'circuitsthrough the relays which have the double function of disconnecting theindividual' line signals and establishing connectionwithlthe subscriberslines when- I ever an operator s'cord-plug is inserted to'make con-.

nection with the line, to provide an improved constructionandarrangement whereby the coil or winding of the individual line relay mayhave two energizing circuits, one a line circuit for initiallyenergizing the relay and the other a local circuit adapted to displaceor supplant the line circuit for the purpose of clearing the line ofcurrent and looking or holding the line signal in operation until theoperator answers the call; and to provide a construction and circuitarrangement whereby a centralized source of talking and signalingcurrent is adapted to supply talking current to the subscriberstransmitters and at the same time energizethe relays which connect thenormally disconnected jacks with the line over' circuits including theflexible connecting cord bywhich theoperator temporarily establishesconnection between any two subscribers lines. I

It is also an object, as will hereinafter more fully appear, to providecertain novel combinations and circuit arrangements which will tend toincrease the genoral efiiciency and serviceaibility of a telephone exthecord or plug circuit. It will be readily under stood that the subscribers substation apparatus can be of any suitable known or approvedcharacter. 'At the exchange or central station, the jacks J and J arenor-. mally disconnected from the subscribers lines to which they areallotted, and the cut-off relays IV- each have one terminal connectedwith the grounded pole of the common battery B and'the other terminalconnected with the sleeve or thimble of the associated jack. It will beunderstood that the batteries B and 'B can be one and the samebattery-that is to say, one

battery c'an'be employed if desired The operatorscordconnecting'apparatus comprises the answering 'plug P and the callingplug P which are, as usual,

similar line relay R at the right is individual to the line leading fromthesubstation S. The supervisory relay n at the left is associated withthe answering plug of the operators cord circuit, and the similarsupervisory relay R at the right is associated with the of course, be ofany suitable known or approved form of construction consistent with themode of operation of the system and the various results and advantagesto be obtained thereby. The arrangement of suchapparatus in a systemembodying the present improvements willperhaps be most readilyunderstood by tracing the circuits existing in the system from-timetotime as the several different'possible connections of thesysteinaremade, as follows: If subscriber S wishes a-conhection hecallsthe operator at the central station by liiting hisreceiver from the hookH. This imme diately completes a circuit from the hook, through thecontact, 1, and the primary -2 of the induction coil. of

thereceiver circuit, and through the line 3,- to one of the armatures 4of. the duplex relay 3., thence through contact 5, lamp L, and. coil ofanother relay R and through connection 6 to battery; thencefrom thebatterythrbughthe groundQconnect-ion E to another ground connection 7and contact 8 to the other-armature?) of the relay R, and thence throughline 10 and trans-' 'mitter T backv to the hook H; The flow of currentthrough. the circuit thus established. will cause. the relay R:toattractitsarmaturer against adjacent contact pointslZ and 13 and closea localrcrosscircuitfrom the line 3 through connection 11, contact, 12,armature.

1', contact 13, and-connection 14 tothe line 10, and the flow of currentresulting in this local circuit will light a signal lamp 1 connectedtherein and thus attract the operators attention to the fact that a.connection is wanted, the flowoicurrent to feed the lamp then being frombattery B, through 6 and R to the lamp and from back to the batteryB.

the lamp-through 5, 4, 11, 12, r, 13, a, s, 7, and, E,

Theoperator rsspondsby placing theplug Pin thesubsci-iberls jack Jwhereupon a circuit will be established from the battery B through animpedance moil 16 and, line 17'to asupervisorylamp l,- andjrom this1lamp-through connection. 18, a sleeve 19of= theplug to the-sleeve 20 ofthejack, thence through connection 21 and thmughthe coil-of -relay Rinto the ground at, 22,

' and, thence through the-earth back tothe: battery by way of groundconnection. 23. The flow of. current through'this circuit wills, causethe reIayR. to attract both-of its armatures 4 and 9,, andatoestablishatalking circuit fromjthe battery through a repeating coil.24 and;

throughthe coil ofa relay R andrconnec'tion 25, 'to theintermediate ring26'of-the plug, and fromthis interme:

- diaterin g through the intermediate spring 27 of the jack andcontact28f: the armature 4- of the relay R. and thence through the line 3, e0112 and contact 1-, to the 1 switch H andtransmitterT; thence backthroughline.

10,, armatur'el), contact 29, tip spring 3;) ofthe jack, tip

j 81 of. the plug and repeating coil,32, thenceto the battry. Theshifting of the armature 4 of the-relay R willialso open the circuitthrough the relay R and-permitits armature r to fly back and disconnectthe contactel2 and 13, thus opening the ,circuit: through thesignal-damp Z, and restoring onexting'uishing, the latter.

heoperator then presses the listening key K andtcome The telephone inpletes a circuit from the battery B through the other side of therepeating coil 32, connection 33, key K. conback tojthe battery. Theoperator can consequently now talk inductively with subscriber-S andfind out thenumber of the station with which connection is wanted. Thismay be assumed to be station S with which the operator proceeds to makeconnection by placing the plug P in the jack J" corresponding to thatstation. The insertion of this piug completes a circuit from the batteryB, through impedance coil 47 and connection 48, to a supervisory lamp Iand from the lamp through a connection 49 to the sleeve 190ithe plug P,thence through the sleeve 20 of the jack by connectionZl to the coil of.theduplex relay R and thence to ground and into the ground at 22, andthence-through the earthand through ground connection 23 ,back to thebattery. The supervisory lamp I will thereupon light iip and. willremain-lighted until the subscriber at station S removes his receiver tfrom the hook. The energizing-of the relay R will also attract armatures4' and 9, against contacts28 and 29, respectively, and'thus enable theoperator to call upstation S by pressing the ringing key K to bring theringing generator G into circuit with the bell of station S The circuitconnections will then be from the generator G through connection 50 andcontact.

51, key Kl, tip 31, tip spring 30, contact 29, armature 9,

line l0, connection 52, contact 53, hook H, and contact 54:to the bell55 and from the bell through condenser56,

line 3, armature 4, contact 28, jack spring 27, plug ring- 26,connection 57, key K contact 58 and connection 59 tip spring 30,-contact, 29, armature 9,- andline 10, to the m transmitter T and-hook Hand thence through contact.

1, induction coil2; line'3, armature4, contact 28, jack 'spring27,plugring26, connection 57, key K contact. 63, connection 64, relay Rconnection40, and.repeat,-.

ing coil 24, backto the battery. This puts stations=S and' S intotalking communication inductively through the repeating coils 24:and'32, and at the same time moves the armature 65 of-the relay R andshort circuits and I, extinguishes the supervisory lamp- 1' through acontact 66 and impedance coil- 67. The re-' placing of the receiver tupon the hook (if-station S will;

however, open the;circuit through relay R? again;and-

drawal of its plug irom its jack. In themeantimathe supervisory-lamp.Z.forstation S'wilLnot have lighted.

owing to .the fact that the sameact of-inserting the =pl ug P whichcompleted :the circuitthrough-thelamp by. way 'oimonnections l7j-and 18, will'alsohavabroughtiaboutt rent from the line.

as with lamp 1., the replacing of the receiver t upon its hook will openthe circuit through the relay R and per mit the armature 65 to drop backand open the shunt,

thus directing the current through the lamp Z causing the latter tolight up and remain lighted until the line to station S is opened by thewithdrawal of the plug P.

Thus it will be seen that the connections 11 and I4,

and the armature r constitute a short circuiting connection orarrangement by means of which the battery B and the relay B may be madepart of either a local or the substation circuit. When a call is sent infrom the substation the local or short circuit immediately closes andtakes up the signaling current and excludes it from the line. stationpractically out of circuit with the battery, and consequently theinsertion of the plug and the operation of the cutout relay R. does notcause an unpleasant sound in the receiver. As stated, the conductors l1and 14 and the armature 1' constitute a short-circuiting connection,which is normally open, but which closes as soon as a call is sent in.This short-circuiting con-' nection is preferably of low resistance andwhen closed operates to effectually exclude the calling signal cur- Inother words, this short-circuiting connection operates to automaticallyshort-circuit the substation from whence the call came. Thisshortcircuited condition of the substation continues until after thelocal circuit has been broken or opened up for the purpose ofextinguishing or restoring the calling signal. In this way, the breakingof the line circuit' in'answering a call does not produce any soundin'the receiver at the substation, inasmuch as no current is onthe lineat the time this breaking of theline circuit occurs. Furthermore, thearrangement has the advantage of enabling the battery B to light lamp -lthrough a short local circuit of comparatively low" and unvaryingresistance. This lamp, which is the calling signal, remains lighted,until' the plug P is inserted in the jack J, regardless of whether thereceiver at the substation is hung up or not.

Preferably, and in order to insure thebest results,

the jacks arenormally insulated frdm the lines. In other-words, eachjack is normally disconnected-from the line to which it is allotted.The. cut-out relays,

however, serve to establish connection between the lines and the jacks,upon the insertion of the cord plugs. These cut-out relays, as stated,also serve to sever the connections between the battery and the lines.Preferably, one terminal of each cut-out relay is per-- manentlyconnected with a source of current, and the other-terminal of such relayis preferably permanently connected with the sleeve'contact or thimbleof the adjacent jack. The coil of each line relay is adapted andarranged to form part ofeither the line or the local line lamp circuit.It will be readily understood that the resistance of thevarious relaysand resistance coils can be adjusted or regulated by those skilled inthe art to give the desired results, and in accordance with theconditions of any particular case. Preferably, the battery for supplyingthe signaling currentrhas both poles normally connected with both sidesof .the line. The jacks and ,the cord-circuit, asillustrated,-arepreferably This leaves the receiver of the sub-.

by those skilled in the art of telephony.

three-way in character, the jacks and plugshaving the usual tip, ring,and'sleeve contacts.

An important feature of my invention-is the energizing of the cut-offrelays R over circuits including the cord strands. As shown, the thirdstrand of the cord is used for this purpose. It will be understood,however, 7 that for this feature of my invention I do not limit my self.to any particularnumber of parallel strands. Furthermore, and as afeature of special improvement, the cord strand energizing circuit forthe cut-off relay is combined with a supervision which is independent ofthe ground between the subscribers stations and the central station.-With this combination, as set forth, the signaling is all carried onover the line, and without using the ground at the substation.

The cut-off relays R not only serve when energized to connect the lineswith the normally disconnected jacks or line terminals, but also todisconnect-the individual line signals from the lines.

The bells or ringers 55 are bridged across the lines, and thecondensers56 stop the flow of battery current through said bells or fingers, butleave the latter responsive to ringing currents supplied from thebridged generator G, whereby the ground is not used for ringi It willalso be seen that I combine acommon bat tery normally disconnected jacksystem with a supervision which is absolutely independent of the aground at the substations.

The short circuit closed by any energized line relay R has the doublefunction of quieting the line and locking or holding the line signal inoperation until the operator answers. Each line relay has two energizingcir cuits, one a line circuit, and the other a local circuit, the latterdisplacing or supplanting the former when the subscriber calls. Both ,ofthese circuits are,- it will be seen, controlled by relay contacts. Theline circuit for initially energizing the line relay includes both sidesof the line in series, substantially as shown.

While I have elected to illustrate all of the features and combinationsof my invention in connection with a full common battery telephonesystem, it will be seen that the said features and combinations are moreor less applicable. to other systems, and for this reason I do not limitmyself altogether to a common battery system. i I Qbviously,xtheforegoing and other features and advantages will be readily understoodand appreciated If my invention or improvements are used change, wheresuch is necessary, it is evident that any well known or suitable form ofbusy test can be employed.

With my improved circuit arrangement and'combinations, the two normallydisconnected jack contacts 27 and 30 are both included in. the talkingcircuit, the

supervisory relay energizing circuit, the ringing circuit, and thebatterycircuit. for the-transmitter T. In this way these two contactswhich are normally discon nected from the line have a'plurality ofimportant functions or functional relations to other elements.

With further reference to the quieting of the line, when the operatorplugs in, 'it will be seen thatthe battery current is removed from.thewinding of the line relay before the short-circuit is removed'fromacross.

in an ex- 115 as previously explained, preventing clicks on noises inthe receiver which the calling subscriber is holding to hisear atthetime that the operator answers the call.

What I claim as my invention is,

1;, In a telephone system, the combination of stationsand lineconnection between the-same, a calling; device at one of saidstati ns, acalling signal and,a battery at the other station, a normally open localcircuit including said battery, said battery being normally cdnnectedwith the line, and a relay for closing said local circuit, the operarion 01' said calling device causing the currentot-said battery to firstflow over the line, the energization of. the relay then operating totransfer thecurrent to said local circuit, and a talking circuitincluding both sides of the calling circuit i 2. In a telephone system,the combination ot= asubstation and a central station, a line circuitconnecting said substation and said central station, a calling device atsaid substation, a calling signal and a relay and a battery at thecentral station, anormally open local circuit including said batteryandrelay, said battery being normally connected with the line, saidlocal circuit when ciosedbythe relay operating to completelyshort-circuit the said substation, so as to permit the operator toanswer a call without producing sounds in the receiver at said station,and-a talking circuit includingboth sidesoi. the calling circuit.

8. in a telephone system, the combination of a substation and a centralstation and suitable line connection between the same, a calling deviceat said substation, a

calling signal at the central station, a relay and a battery at saidcentral station, a normally-open local circuit inciuding saidbatteryandrelay, said relay and said calling signal being responsive to saidcallingdevice, and the local circuit when closed by the relay operatingto hold or iock the calling signal in operation until the call isanswered-by the-operator, and-a talkingclrcuit including both sides. ofthe calling circuit,

4. Ina telephone system, the combination or a sub station and a centralstation, suitable line connection between said stations, a hook-switchat the sub station for opening fllld' closing the line circuit, aspring-jack at the central station normally insulated from the line, anormally open short-circuit connection across thetwo limbs 01' thelineat the central statlon, a battery normally connected with one limboi. the line, a line relay for operating a line signal and arranged toclose-said normally open short-circuit connection, a normally open localcircuit in-- ciudlng said relay and battery, and also including saidshort-circuit connection, a cord circuit having a plug adapted forinsertion in said jack, said cord-circuit. being connected with asuitable source of current supply, and a cut-out relay adapted to beenergized when the'plug is inserted in the jack, said cut out. relaywhenenergized establishing connection between the jack and theline, andalso operating to break the said local circuit and denergize' said linerelay.

5. In av telephone system, a substation and a central-station and lineconnection between the same, -a calling signal and a battery foroperating the same atthe central station, said battery and signal beingnormally connected with the line, the signal serving as a mediumofconnection between the battery and line, a calling device at thesubstation -1or operating said calling signal, theline being normallyopen at the substation and a normally open local circuit which closeswhen a call is sent in and which holds the calling signal in operationuntil restored\by the operator, and a talking circuit including bothsides of the calling circuit.

6. In a telephone system, a substation and-1a central staf tion andnormally open line connection between the same, a calling signalconsisting oi. a lamp arranged to light when a call is sent in fromthesubstation, a relay associated withsaid lamp :1 suitabiedevice at thesubstation-- tor causingthe operation otssid calling signal, abattery atthe central station for supplying current to said lamp said batterybeing normally connected with the line through said relay and lamp, anda local circuit. which is closed when a call is sentin and which aflordsa short circuit of comparatively low and. unvarying resistance throughwhich the current from said battery purpose oi. lighting said lamp.

7; A telephone system comprising a substation, with the normally openline thereof a battery and relay at the centlfll-Stdiilflll,saidiinenormally connected with thebattery and relay at the centralstation, a local circuit normally.

open but closed-by said relay when a call is sent in from saidsubstation, said local circuit when-closed operatingto exclude thecurrentot said battery from the substation, a calling signaldlsplayed=when saldlocaLcircuit is. closed, and a circuit. breakingdevice for opening said localclrcuit, a metallic talking clrcuitfandmeans for using both sides of said talking circuit in calling. Q i

8. A telephone system comprising a substation and a central station withline connection, a battery and a local circuit. at the central station,a relay for closing the current of said battery through said localcircuit when a cal1 line through said relay, and the relay forming apart of both line and local circuits, a calling device at the substationfor operating said relay, and a calling signal at the central stationassociated with said relay and operated by said battery, and a talkingcircuit including both sides of the calling circuit.

is sent in the battery being normally connected withthe 9. In atelephone system, a substation and a central station with completemetallic line connection between the same, a relay and calling signaland a battery for operating the same at the central station, ashort-circulting connection between the line terminals at the centralstation;

said short-circuit connection being normally open, a calling device atthe substation adapted to operate said relay and thereby close saidshort-circuit connection, the said caiiingsignai being also responsiveto said calling device a local circuit including the battery and reiayand shortcircuit connection, the said short-circuiting connectionoperating to exclude the current of saidbattery from the substation lineas soon as the relay is operated by a. call, and

a circuit-breaking device for opening said local circuit and therebyrestorifig said signal.

10. In a telephone system, a substation and a; central station and acomplete metallic line connection between the same, a calling device atthe substation, a lamp and a relay and a battery for operating the sameat'the central station, and a short-circuit connection between thesubstation line terminals at the central station, said shortclrcuitingconnection being normally open but closed by said relay when a call issent in, said relay and short-circuiting connection forming part of alocal circuit of comparatlvely lowvand unvarying resistance throughwhich the I current from said battery flows for the purpose of. lightingsaid lamp, and a circuit-breaking device for openingup said localcircuit andresforing or extinguishing said lamp.

11. In a telephone system,-. a substation and a centralstation andcomplete metallic line connection between the same, a lamp signal andarelay and abattery for operating the same at the central station, ashort-circuitconnection between the line terminals at the centralstation, said short-circuit connectionbeingnormally open, and a callingdevice at the substation for. operatingmiaid relay andtherebyclo'singthe said short-circuit, a cut-out relay jor open ing up saidshort-circuit connection and extinguishing said lamp, a spring-jack anda plug and cord circuit with a battery for operating said cut-out relay.

12. In a telephone system, a substation anda. central station and acomplete metallic line connection between the same, a spring jack and aplug and a cord circuitwith a clearing out signal, a complete metallicline circuit which is opened to operate said clearing-out signal, a.calling signal ands reiayand a battery for operating the same at thecentral station, a short-circuit connection between the terminalsof theline at the central station, said short-circuit connection beingnormally open a local circuit including the battery and relay andshort-circuit connection, and a calling device at'the substation foroperatingsaid reiayandthereby closing said shortficlrcuit connectionnormally open, a signal lamp and a relay and a battery foroperatiug thesame located at the central station, a normally open local circuitincluding said battery and relay,

and also said normally open connection, a receiver-hook or switch at thesubstation for operating said relay and thereby closing the saidnormally open connection between the line terminals, sons to causecurrent from said battery to flow through said lamp, 0. spring jack anda plug and a cord-circuit with a clearing out signal, and suitableconnections for supplying battery current to the line through thetalking strands of said cord-circuit, the complete metallic line circuitbeing opened to eltectthe operation of said clearing-out signal.

il-i. In a" telephone system, the combination of a substation and acentral station with a complete metallic line connection between thesame, a short-circuit connection be tween the line terminals at thecentral station, a relay having its armature adapted and arranged toclose said short-circuit connection when a'call is sent in from saidsubstation, a battery which operates the relay when the calling deviceat the'substatlon is operated, the short-circuit connection when closedforming part of the local circuit for the current of said battery, acalling signal lamp located in said local circuit at a point outside ofsaid short-circuit connection, the-latter when closed thereby hperatingto exclude the current of the signal battery from the main line,acut-out relay for opening-up said.

short-circuit and thereby extinguishing said lamp, a spring jack havingsuitable connection with said cut-out relay, a plug and cord circuitwith a battery, :1 clearing-out signal in said cord circuit, and acomplete metallic-line circuit which is'opened to operate saidclearing-out signal.

. 15. In a telephone system, the combination of asubscriber's line, ahook. switch for opening and closing the line circuit, abattery normallyconnected with the line, a line relay for operating 'the line signal, anormally open short-circuit connection across the line terminals at thecentral station, said short-circuit connection being closed by theenergization of the line relay when a,call is sent in,

and a local circuit including said battery relay and'shortcircuitconnection, the said relay being located in a' conductor formingpart oiboth the line and local circuits.

16. In a telephone system,- a line circuit normally openat one station;a switch or like circuit-changer therefor at said station a source ofcurrent, a relay, and a signal receiving device all at another station,and a normally open associated local circuit atsald other stationleading through the contact points of said relay and controlled thereby;the said source, relay, and signal device being in a section ofconductor forming part of both line and local circuits. 17.The-combination in a centrul battery telephone ex change, of a-malncircuit normally open at a substation and extending therefrom to acentral station and a circuit-changing switch therefor at saidsubstation; with a normally open associated local circuit, a source oi!current, a relay responsive to the operation of said circuitchanger anda signal receiving devlceyall at said central station; the said source,the magnet of said relay, and the signal device being serially connectedin the main circuit, and together with contactpoints of said relay inthe associated local circuit also; and the said relay" constituting aswitch to close said local circuit, and to divert the current of thesource from said main circuit through the said local circuit for theoperation of said signal device.

18. mn telephone system, thecombination of a, me-

tallic main circuit normally open at a. substation and ex tendingtherefrom to acentral station; a clrcuit-changing switch therefor atsaid substation; and an earth conncction normally attached to one mainconductor of said metallic circuit at said central station with a sourceof current, agcutoff relay controlling the conection of said source withthe. main circuit conductors; an independent relay responsive to theaction of said circuit-changer; and a normally detached auxiliary earthconnection for the other main conductor of said metallic circuit leadingthrough and controlled by the contact points of said independent relay;the said source and the magnet of said independent relay being seriallyconnected in the main circuit; and the said auxiliary earth connectionbeing branched from its associated main conductor at a point external tothe cutoif relay connection of said source;

whereby a short circuit for said source is constituted be tween the saidtwo earth connections immediately pursuant to the operation of saidsubstation circuit-changer to transmit a call signal, and the consequentoperation of said independent relay.

19. In a central battery telephone exchange system, the combination witha main or subscribers circuit normally open at a substation andextending therefrom toa central station; a telephone receiver and atelephone suspension switch both at said substation, the latter beingadapted on the removal of said receiver therefrom to close said circuitand thereby transmit a call signal to said central station; a batterysupplying current to said main circuit; switchboard devices foranswering call signals transmitted over saidmain circuit by theoperation of said substation switch; and a cutod' relay responsive tothe normal operation of said switchboard devices, and acting to severthe normal connection of said battery with said main circuit, all atsaid central station; of associate switching and signaling devices, alsoat said central station, comprising an independent relay responsive tothe signaling operation of said suspension switch, and asignalu'eceiving device controlled thereby, bothnormaily connected inseries in said main circuit together with said battery; and meansactuated by said independent relay for short-circ'ulting the current ofsaid battery through said relay and signal device when acall signal istransmitted from said substation, and before said cutoff relay isoperated by said switchboard call answering devices to sever theconnection of said battery with said main circuit.

20. In a central battery telephone exchange system, the combination witha main or subscribers circuit normally open at a substation andextending therefrom to a central station; a telephone receiver and atelephone suspension switch, both at said substation, the latter beingadapted on the removal of said receiver therefrom to close said circuitand therebytransmit a call signal to said central station; a batterysupplying current to said main circuit; switchboard devices'foranswering call signals transmitted over said main circuit by theoperation of said substation switch; and acutofi relay responsive to thenormal operation .of said switchboard devices, and acting to sever thenormal connection of said battery with said main circuit all at saidcentral station; of associate switching and signaling devices, also atsaid central station, comprising an independent relay, and a signalreceiving device controlled thereby both normally connected togetherwith said battery in ,series in said main circuit; and a normally, openlocal circuit leading through the contact pointsof said relay, and alsocontaining said battery, relay, and signa device; the said relay beingresponsive to call signals msmitted by said suspension switch, andadapted when operated to close the'said local circuit, and therebydivert the battery current from the main circuit thereto; whereby thesaidsignal device may be operated by current flowing in said localcircuit, and maintained in operation by said relay, and whefeby abruptchanges in the electrical condition of 'the main circuit when thebattery is disconnected therefrom by the cutofli relay, and soundsproduced by such changes in the substation receiver may be prevented.

21. In a telephone system the combination of subscribers lines,subscribers hook switches for opening and closing the line circuits,jack springs normally insulated from the line, a battery normallyconnected with the lines, line relays for operating line signals andadapted to be energizcd when the line circuits are closed by the saidhook switches, normally open connections across the line terminals atthe centrahstation, said normally open connections being closed when thesaid line relays are energized, an operator's cord-circuit provided withplugs adapted for insertion in said jacks. saidlcord-circuit beingconnected with a suitable source of current supply, local circuitsincluding said battery and line relays and also including saidnorniallyopen connections, cut out relays connected and z 'i'aiiged to.be energized by the insertion of the said plugs in said jacks. said cutout relays when energized establishing connection between the jacks andthe'lines, and also operating to break the said local circuits anddeeuerg .c said line-relays.

2 A telephone system comprising a' subscriber's line consisting of twometallic limbs, suitable substation apparatus. suitable central station.apparatus, a normally open low resistance connectionv across theterminals of the two limbs at the central station. and a relay forclosing said connection. said connection, when closed operating toshort-circuit the'said substation apparatus.

'23. in a telephone system. the combination of a subscriber's line.means for closing the line, a three-way also including said line relay,

spring jack normally insulated from the line, a three-way cord circuitprovidedwlth a plug adapted for insertion in said jaclca central sourceof current supply connected with the line and the cord-circuit. a linerelay for operat ing a calling-signal, a cutout relay for establishingconnection between the jack and-the line, said cut-out relay beingenergized by the insertion of the plug in the jack, :1 local circuitincluding said source of current supply, and said local circuit beingbroken when the cut out relay is energized, and the local circuit forsaid cut out relay including said source of current supply and alsoincluding the sleeve'contacts of the jack and plug and the third strandof the cord-circuit.

Z-i. In a telephone system. the combination of a subscriber's line, asubscrihers hook-switch for opening and closing the line,.a spring-jacknormally insulated from the line. an operator's cord circuit having aplug adapted for insertion in said jack. a line signal, adapted to beoperated when the line circuit is closed. a source of current connectedwith the cord circuit, a cut-out relay for establishing connectionbetween the line and the jack, said cutout relay being energized whenthe plug isinserted in the jack, one terminal of said cut-out relaybeing permanently connected with said source. of current supply, thelocal circuit of said cut-out relay including the sleeve contacts of.

the jack and the plug.

' In a telephone system, the combination of a subscrlbers line. asubscriber's hook switch for opening and closing the line circuit. athree-way spring jack normally insulated from the line, an operator'sthree-way cord-circult provided witha plug adapted for insertion in saidjack. a battery bridged across the strands of the cordcircuit, a linesignal adapted to be operated when a call is sent in and theline-circuit closed, a cut-out relay for restoring said line signal andadapted to establish connections between the jack and the line, saidcut-out relay having one terminal connected with a sleeve or testingring of said jack, and the other terminal of said cutout relaybeingpermanently connected with said source of current supply.

26. In a telephone system, the combination of a subscribers line. asubscribers hook-switch for opening and closing the line circuit, anormally open connection across the line terminals at the centralstation, a source of cur rent supply normally connected with the line, aline relay adapted to be energized when a call is sent in, and arrangedto close said normally open connection, a spring jack and an operator'scord'circuit provided with a plug adapted for insertion in said jack, asupervisory lamp associated with said cord-circuit, a normally openshunt around said lamp adapted to be closed while the plug" is insertedin the jack and the line-circuit is closed and a cut-out relay forrestoring the line signal and adapted to be energized when the plug isinserted in said jack.

27..In a telephone system. the combination of a subscriherFsline, asubscriber's hook switch 'for opening and closing,tl1e-line. aspring-jack normally insulated both from vthe line and the ground, asource litcui'i-ent connected with theoperator's cord circuit.a'normally open short-circuit connection across the'linr terminals atthe central station, a line relay adapted to respond to calls sent infrom the 'sub-stationand arranged to close said I' normally openshort-circuit connection. a line signal oper ated by said line relay. a.-ut-out relay for restoring said line signal and adapted to establishconnection between the "jack and the line. the said cut-out relay beingener gized by theinsertion of the plug in the jack, a supervisory lampassociated withthe shunt around said lamp. said shunt being closed whilethe plug is in the jack andthe line circuit closed, but said shuntopening and causing said lamp to glow when the line circuit is broken.

28. In a telephone system, the combination of sub-stations and a centralstation, complete metallic line connections between said stations,subscribers hook switches at the sub-stations for. opening and closingthe lines, springjacks at the central station normally insulated fromthe lines. normally open short-circuit .connections across the lineterminals at the central station, a source of current normally connectedwith the lines, line relays adapted to be energized by the closing ofthe line circuits and to close said normally open short circuitconnections, line lamp signals in series with said line relays, anoperators cord circuit provided with plugs adapted for insertion in saidjacks, a source of current bridged across the said cordcircuit.supervisory lamps associated. with said cord-circuit, normally openshunts around said supervisory lamps, said shunts being closed while theplugs are in the jacks and the line circuits closed, but said shuntsbeing'opened controlling said shunts, and cutout relays for restoringthe line signals and establishing connection between the be energized bythe insertion of the plugs in the jacks, each cut-out relay havingoneterminal permanently connected with the source of current connectedwith the cord circuit, and the other terminal of each cut-out relaybeing cent spring-jack.

relay,. means for supplying current through the line' circuit forinitially energizing said relay, a normally open local circuitassociated with said line signal, the coil and thenormally separatedcontacts of said relay being included in said'local circuit, the 'relaycoil being also included in the line circuit, and means'for calling overboth station and complete metallic line connection between the same.' alamp signal ,and a relay and a'battery for operating the some atthecentral station, a short-circuit connectioubetwcen the line terminalsat the central station, said short-circuit connection being normallyopen, and a calling device at the substation for operating said relayand thereby closing. the said.short-circuit, a cutting-out said battery,a spring jack and a plug and cord :1 battery for operating said cut-outrelay.

32. The combination with a telephone line and a connection terminaltherefor normally not in operative relation with said line. of aconnecting plug and cord'circuit adapted to cooperate with said line, asupervisory signal controlling magnet and a battery associated with saidcord circuit, a switch at the subscriber's station, and means controlledby the insertion of the plug 'into the jack for placing said jack inoperative relation with the line \vhei ebysa'id signal controllingmagnet is placed under the control of the subscriber.

circuit with 33. The combination with a.telephone line and a con nectionterminal in the form of a spring jack normally not in. operativerelation with said line, of a cord circuit and connecting plug.supervisory signaling apparatus associated with said circuit, a centralsource of current associated with said line and circuit to operate saidsupercord-circuit, and a normally open" when the line circuits arebroken, supervisory relays for,

jacks and the lines, said cut-out relays being adapted to 1 connectedwith the sleeve. contact or thimble of the adja- 29. In a telephonesystem, the combination of a 'sub .scribers line, a line relay, a, linesignal operated by said 31. in a telephone system, a substation andscentral relay for opening up said short-circuit and cutting out.metallic circuit for talking purposes, means for operating said relayfrom said source when connection is made with the line by currentflowing over a path including a portion of the cord circuit, and meansfor sending a calling-current over the line of the,called subscriberonly and at the same time maintaining said relay in operated condition.

35. The combination with a telephone'line and a con.

nection terminal therefor normally not in operative relation with theline, of a connecting plugand cord-circuit to coiiperate with said line,a supervisory signal controlling magnet and battery associated with saidcord-circuit, a telephone transmitter and a switch at the subscribersstation, and means controlled by the insertion of the plug into the jackfor placing the jack in operative-relation with the line by currentflowing over a path includinga portion oi? v the cord-circuit, wherebytalking'current is furnished to said transmitter and said magnet isplaced under the control of the subscriber.

36. The combination with a telephone line, and a connection terminaltherefor normally not in operative relation with said line, of aconnecting plug and cord circuit adapted to codperate with said line, asupervisory signal controlling magnet and a battery associated with saidcord circuit, a switch at the subscriber's station, and means includinga contact connected with the cord circuit controlled by the'insertlon ofthe plug into the jack for placing said jack -in operative relation withthe line,-

whereby said signal controlling magnet is placed under the control ofthe subscriber.

37. The combination with a telephone line and a connection terminal inthe form of a spring jack normally not in operative relation with theline, of a cord circuit and a connecting plug, a central source .ofcurrent associated with said line and circuit to furnish talking currentto the substations, and means including said source -01 current actuatedby the insertion of said plug in the jack and by current flowing over apart of the cord circuit' for placing said jack in operative relationwith said line.

38, The combination wlth a telephone line and a connectlon terminal inthe form of a spring jack normally not in operative relation with saidline, of a cord circuit and connecting plug, supervisory signalingapparatus associated with said circuit, a central source of currentassociated with said line and circuit to operate" said .supervisoryapparatus, and a relay adapted'to be energized from said source over apath including a portion of the cord circuit to place said jack inoperative relation with the line when said plug is inserted in saidjack.

39. The combination with a telephone line, and a connection terminal inthe form of a spring jack, of a connecting plug and a cord circuit, acentral source of current associated with said line and circuit tofurnish current for talking purposes, supervisory signal apparatusassociated with the cord circuit and operated from said .source ofcurrent, and a relay actuated from said source'by the insertion of saidplug into and its withdrawal from said jack for controlling theoperative relation of said jack with said line, said relay beingactuated by current flowing over a portion 01' a strand of the cordcircuit, a contact of the plug andjack.

40. In a telephone system, a metallic circuit line, a con a cordcircuit, a signaling device normally in operative relation with saidline, a central source Jot current and supervisory signaling apparatusassociated with-said line and cord circuit, said source being adapted tofurnish current for the operation or said apparatus and for talkingpurposes, and l relay actuated from Ilid source over a'portion ot-thecord circuifwhon' Illd plug in insertedin said jack to place llldsignaling device in inoperative relation with said line and said jack inoperative relation with said 'line. l

41. The combination with a telephone line having a limb extending to thecentral station,of a linecontact for said limb normally disconnectedtherefrom, a c0rd,circuit and connecting plug. supervisory signalingapparatus c0nnected with said circuit, a central source of currentassociated with said line and circuit to furnish current for talkingpurposes, and for the operation of said supervisory apparatus, and meansactuated over a portion of the cord ,current for talkingpurposes and forthe operation of said apparatus, and a relay energized from said batteryand connected directly-t0 the cord circuit and adapted to disconnectsaid limb from said signaling device and to connect the same with theline contact when ,a connection is established with the line. Y

43.- The combination witlra telephone line having a limb extending tothe central station, ofa spring or moving part with which said limbconnects at the central oiiice, a signaling device connected with saidspring or part in its normal position, a line contact for said limb, acord circuit and connecting plug, ,a central battery associated with thesaid line circuit, supervisory signals also asso' ciated with thecircuit, said battery being adapted to furnish current to thesubstations for talking purposes and for operating said supervisorysignals, and a relay'also energized from said battery over a circuitincluding a portion of the cord circuit and adapted to disconnect saidspring or part from the signaling device and to connect it with the linecontact when a connection is established with the line.

44. In a telephone system, the combination of a'subsc'ribrs line, a jackhaving linecontacts bothfot which are normally disconnected fromtherline, a cord circuit and plug, a relay'for connecting the jack withthe line, and a battery for energizing said relayover a pathincluding'the sleeve of said plug and a strand or said cord circuit.

45. The combination of a. subscribers line, a jack having line-contactsboth of which are normally disconnected from the line, a relay forestablishing connection between the jack and the line, 1a cord circuitand plug, and a battery for energizing said relay over a path includingthe sleev contacts of said jack and plug. 7

-16. The combination of a subscriber's line, a jack normallydisconnected from the line, a relay for establishing connection betweenthe line and said jack, a cord circuit and plug, a supervisory relay anda supervisory lamp associated with said cord circuit, and a battery forenergizing both of said relays and lighting said lamp, the said firstmentioned relay being energized over a path including said lamp.

47. A telephone system comprising a subscribers line, both sides ofwhich are normally disconnected from the spring jack, an electro magnetfor an opening and closing connection between the line and spring jack,and a central source of current and an operators cord strand included inthe energizing circuit 0! said magnet.

48. The combination with a telephone line and a connection terminaltherefor normally not in operative relation with said line, of aconnecting plug and cord circuit adapted to cooperate with said line, asupervisory signal controlling magnet and a battery associated with saidcord circuit, a switch at the subscriber's station, and means controlledby the insertlon of the plug into the jack for placing said jack inoperative relation with the line, whereby said signal controlling magnetis placed under the control or the subscriber, together with asupervisory or disconnecting circuit including both sides of said linein series, and a substation switchfor opening said supervisory circuitto give a signal.

49. The combination with a telephone line and a connection'terminal inthe form of a spring jack normally not in operative relation with saidline, of a cord circuit andconnectingplug, supervisory signalingapparatus associated with said circuit, a central sourcev of currentassociated with said line and circuit to operate said supervisoryapparatus, and a reiay'adapted to be energized from said source to placesaid jack in operative relation with the line when said plug is insertedinto said jack, together with a supervisory or disconnecting circuitincluding both sides of said line in series, and a substation switch foropening said supervisory circuit to give asignal.

50. In a telephone system, a subscribers line, a line relay, a centralsource of electric current, a normally open line circuit for energizingsaid relay, and a normally open local circuit controlled by the saidrelay and including an energizing coil thereof, whereby the said localcircuit is substituted for the said line circuit when the relay isenergized, each circuit including said source of current, and the saidapparatus thus provided including relay contacts controlling said linecircuit, 'and an armature i'or operating said contacts.

51. In a telephone system, the combination of stations and lineconnection between the same, a calling device at one of said stations, acallng signal and a battery at the other station, a normally open localcircuit including said battery, said battery being normally connectedwith the line, and a relay "for closing-said local circuit, theoperation of said calling device causing the current oi. said bat teryto first flow over the line, and the energization of the relay thenoperating to transfer the current to said local circuit, a normallydisconnected jack, a relay individual to the line and adapted whenenergized to connect the jack therewith, an operator's connecting cord,and a local energizing circuit for said individual relay, said cord.

'52 In a telephone system, the combination of a substation and a centralstation, a line-circuit connecting said sub'station and said centralstation,-a calling device at said substation, a calling signal and arelay and a bator lock the calling signal in tery at the centralstation, a normally open local circuit including said battery and relay,said battery being nor- "m'ally connected with 'the line, saidlocal'circuit when closed by the relay operating to completelyshort-circuit the said substation, so as to permit the operator toanswer a call without' producing sounds in the receiver at said station,a normally disconnected jack, a relay individual to the line and adaptedwhen energized to connect the jack therewith, an operator's connectingcord, and a local energizing circuit, for said individual relay, saidenergizing circuit including a strand of said connecting cord. 53. In atelephone system, the combination of a substation and a central stationand suitable line connection between the same, a calling device at saidsubstation, a

calling signal at the central station, a relay, and a battery at saidcentral station, a normally ,open local circuit ineluding said'batteryand relay, said relay and said calling signal being responsive to saidcalling device, and the local circuit when closed by the relay operatingto hold operation until the call is answered by the operator, a normallydisconnected jack, a relay individual to the line and adapted whenenergized to connect the jacktherewith, an operator's connecting cord,and a local energizing circuit for said individus relay, said energizingcircuit including a strand of said connecting cord.

54. In :1 telephone system, a substation and a central station and lineconnection between the same, a calling signal and a battery foroperating the same at the central station, said'b'at'tcry and signalbeing normally connected with the line, the signal serving as medium ofconnection between the battery and line, a calling device at thesubstation for operating said calling signal, the line being normallyopen at the substation, and 8. normally open local circuit which closeswhen a call is sent in and which holds the calling signal in operationuntil restored by the operator, a normally disconnected jack, arelayindividual to the line and adapted when energized to connect the jacktherewith, an operator's connecting cord, and a local energizing circuitfor said individual relay, said energizing circuit including a strandof'said connecting cord.

55, In a telephone system, a substation and a central station andnormally open line connection between the same, a calling signalconsisting ofa lamp arranged to light when a call is sent in from thesubstation, a relay associated with said lamp, station for causing theoperation of said calling signal, a battery at the central station forsupplying current to said lamp, said battery being normally connectedwith the line throughsaid relay and lamp, and a local circuit a suitabledevice at the subwhich is closed when a call is sent in and whichattords a shortcircuit of'comparatively low and unvarying resistancethrough which the current from said battery flows for the purposeoflighting said lamp a normally disconnected jack, a relay individual tothe line and adapted when energized to connect the jack therewith, anoperators connecting cord, and a local energizing circuit for saidindividual relay, said energizing circuit including a strand of saidconnecting cord.

56. In a telephone system, ,a substation and a central station and acomplete metallic line connection between the same, a spring jack and aplug and a cord circuit with I a clearing-out signal, a completemetallic line circuit which is opened to operate said clearing-outsignal, a calling sig' nal and a relay and a battery for operating thesame at the central station, a short-circuit connection between theterminals 01 the line at the central station, said shortcircuitconnection being normally open, a local circuit including the batteryand relay and shorbcircuit connection, and a calling device at thesubstation for operating said relay and thereby closing saidshort-circuit connection to exclude the signal current from the mainline after a. call is sent in, a normally disconnected jack, a relayindividual to the line and adapted when energized to connect the jacktherewith, an operators connecting cord, and a local energizing circuitfor said individual relay, said energizing circuit including a strand ofsaid connecting cord.

57. In a telephone'system, a line circuit normally open at one station;a switch or like circuit-changer therefor at'said station; a source ofcurrent, a relay, and a signal receiving device all at'another station;and a normally open associated local circuit at said other stationleading through the contact points of said relay and controlled thereby;the said source, relay, and signal device being in a section ofconductor lforming part of both line and local circuits; a normallydisconnected jack'; a relay individual to the line and adapted whenenergized to connect the jack therewith; an operator's connecting cord,and a local energizing circuit for said individual, relay, saidenergizing circuit including a strand of said connecting cord.

'58. -A telephone system comprising a substation and a central stationwith line connection, a battery and a local circuit at the centralstation, a relay for closing the current of said battery through saidlocal circuit when a call is sent in, the battery being'normallyconnected with the line through said relay, and the relay forming a partof both line and local circuits, a calling device at the substation foroperating said relay, and a calling signal at the central stationassociated with said relay and operated by said battery, a normallydisconnected jack, a relay individual to the line and adapted whenenergized to connect the jack therewith, an operator's cord, and a localenergizing circuit for said individual relay, said energizing circuitincluding a strand of said connecting cord 59; In a telephone system,the combination of a subscriber's line, a hook switch for opening andclosing the line circuit. a battery normally connected with the line, a

line relay for operating the line signal, a normally open short-circuitconnection across the line terminals at the energizing circuit for saidindividual relay, said energizing circuit including a strand of saidconnecting cord.

60. In atelephone system, the combination of a sub scriber's line, aline relay, a line signal operated by said and a local energizingcircuit for said individual relay,

said energizing circuit including a strand of said connecting cord.

61. In a telephone system, the combination of a subscribers linecircuit, a local circuit at the central exchange,

means for supplying. current through said circuits,-a line relayresponsive to calls and adapted for closing said local circuit, the coilof said relay being connected and arranged to'form part of both line andlocal circuits, and

a line lamp located in said local circuit, a normally disconnected jack,arelay individual to the line and adapted when energized to" connect thejack therewith, an operators connecting cord, and a local energizingcircuit for said individual relay, saidenergizing circuit including astrand of said connecting cord.

62. A telephone system comprising a subscribers line consisting or twometallic limbs, suitable substation apparatus, suitable central stationapparatus; a normally open low resistance connection across theterminals of the two limbs at the central station, and a relay forclosing said connection, said connection when closed operatingtoshort-circult the said substation apparatus, a normally disconnectedjack, a relay individual to the I line and adapted when energized toconnect the jack therewith, an operators connecting cord, and a localenergizing circuit for said individual relay, said energizing circuitincluding a strand of said connecting cord.

I 63. In a telephone system, the combination of stations and lineconnection between the same, a calling device at one of said stations, acalling signal'and a battery at the other station, a'normally open localcircuit including said battery, said battery being normally connectedwith the line, and-a relay for closing said local circuit, the operation of said calling device causing the current of 'said battery tofirst flow over the line, and the energization of the relay thenoperating to transfer the current to said local circuit, asupervisory'relay,and a complete metallic line circuit for energizingsaid supervisory relay.

64.- In a telephone system, the combination of a substation and acentral station, a line circuit connecting said substation and saidcentral station, a calling device at said substation, a calling signaland a relay and a battery at the central station, a normally open localcircuit including said battery and relay, said battery being normallyconnected with the line, said local circuit when closed by the relayoperating to completely short-circuit the said substation, so as toremove liattcrycurreut therefrom and permit the operator to answer acall without producing sounds in the'recei'ver at said station, asupervisory relay, :1 complete metallic line circuit for energizing saidsupervisory relay, and a talking circuit inclnding'said calling device.

(lfi'fln a telephone system, the combination of a substation and'acentral station and suitable line connection between the same, a callingdevice at said substation, a. 'talking circuit including said callingdevice a calling signal at the central station, a relay'and a battery at'said centralstation, a normally open'local circuit including saidbattery and relay, said relay and said calling signal being responsiveto said calling device, and the local circuit whenclosed by the relayoperating to hold or lock the calling signal in operation until the callis answered by.

the operator-,m supervisory relay and a complete metallic line'circuitfor energizing said supervisory relay, from said battery. I 7

.66. In a telephone system, a substation and a central station and lineconnection between the same, a calling signal and a battery foroperating the same at the central station, said battery and signal beingnormally connected with the line, the slgnal'serving asmedium'otconnection between the battery and'line, a'calling device at the sub-'stationfor operating said calling'signah, thelinebeing' normally openat the substation, and. if normally open local circuit which closes whena call is sent mind which holds thecalling signal in operation untilrestored by the operator, a supervisory relay, and a complete metallicline circuit for energizing said supervisory relay.

67. In a telephone system, a substation and a central station andnormally open line connection between'thesame, a calling signalconsisting of a lamp arranged to" light when.a-call is sent in from thesubstation, a relay associated withv said lamp, :1 suitable device atthe sub; station for causing the operation of said calling signal,

a battery at the central station tor supplying current to said lamp,said battery being normally connected with the line 'throughsaid relayand lamp,-and a local clrcuit'wlilch is closed when a call is sent inand which aflords a short circuit oi. comparatively low andunvarylngresistance through which the current from said battery flows for thepurpose of lighting said lamp, asupervisory relay;.aud a completemetallic line circuit for energizing said superv visory relay.

68. In a telephone'system, a substation and a central station and acomplete metallic line connection between the same, a spring jack and aplug and a cord circuit with .operating said relay and thereby closing.said short-circuit connection so as to exclude the signal current fromthe mainline after a call is sent in, a supervisory relay, and acomplete metallic line circuit for energizing said supervisory relay. I69. In a telephone system, a line circuit normally open at onestation; aswitch or like circuit-changer therefor at said station; a source ofcurrent, a relay,'and a signal receiving device all at another station;and a normally open associated local circuit at said. other stationleading through the contact points. or said relay and controlledthereby; the said source, relay, and signal device being. in a-sectionof conductor forming part ofbothline and local circuits;v a supervisory.relay, and a complete metallic line circuit for energizing saidsupervisory relay.

70. A telephone systemgcomprlsing a substation and a central stationwith line connection, a battery and a local circuit atthe'central-station, a relay for closing the cur rent of said batterythrough said local circuit when a call is sent in, the battery beingnormally connected with the line through a winding of said relay, andthe relay winding'and battery forming a part of both line and localcircuits, a calling device at the -substation for operating said relay,and calling signal at the central station associated with said relay andoperated by said battery, 21

energizing said supervisory relay.

71. In a -telephone system, the combination of a subscriber's line, ahook switch for opening and closing the line circuit, a battery normallyconnected with theline, a line relay for operating the line signal, anormally open short-circuit connection across the line terminals at thesupervisory relay, and-a complete metallic line'circ'uit for.centraLstatiOn, 'sdid short-circuit connection being. closed by theenergization of the line relay when a call is sent in, and a local.circuit including said battery relay and short-circuit connection, thesaidrelay being located in a 'conductor forming part of both the lineand local circuits, a supervisory relay, an'da complete metallic linecircuit for energizing said supervisory relay.

72.- In a telephone .system, the'combination of a subscribers line, aline relay, a line signal operated by said relay, means. forsupplyingcurrent through the line circuit for energizing said relay, and anormally open local circuit associated with "said line signallpth'e coiland \the znor mally separated contacts of said relay belng included insaid local circuit, and the relay coil being also included in the linecircuit. a supervisory relay, and a complete metallic line circuit forenergizing said supervisory relay. '73. In a telephone system, thecombination of a sub scribers line circuit, a local circuit at thecentral exchange, means for supplying current through said circuits, aline relay responsive to calls and adapted for closing said localcircuit, the coil of said relay being connected and arranged to formpart of both line and local circuits,

and a line lamp located in said local circuit, a super- 75. In atelephone system,' the combination of stations and line connectionbetween the same, a calling device at one of said stations, a callingsignal and a battery at the other station, a normally open local circuitincluding said battery, said battery being normally connected with bothsides of the line, and a relay for closing said local circuit,

the operation of said calling device causing the current of said batteryto first flow ovcr'both sides of the line, and

the energizing of the relay then operating to transfer the current'tosaid local circuit, an operators connecting cord.

and a supervisory signal under the control of the sul)-- scriher whenthe cord is connected with the line.

76. Ina telephone system, the combination of a substation and a centralstation, a lineconnecting said substa tion and said central station, acalling device at said substation, a calling signal and a relay and abattery at the central station, a normally open local circuit includingsaid battery and relay, a line circuit closed while the subscriber iswaiting for the operator to answer, and including the battery in serieswith the receiver at the substation, said battery being normallyconnected with the line, said local circuit -when-closed by the relayoperating to completely shunt or short-circuitthe saidsubstation, toremove bat tei-ycurrent therefrom and permit the operator to answerwithout producing sounds in the receiver at said' station, an operator'sconnecting cord, and a supervisory signal under the control of thesiibscriber when the cord is com nected with the line,

17. In a telephonc system, the combination of a substation and acentralstation and suitable line connection between the same, a calling deviceat said substation, a calling signal at the central station, a relay anda battery at said central station, a normally open local circuitincluding said battery and relay, said relay and said calling signalbeing responsive to said calling device, and the local circuit whenclosed by the relay operating to hold or lock the calling signal inoperation until the call is answered by the operator, anoperator-sconnecting cord, a talking circuit including both sides of the callingcircuit, and a supervisorysignal under the control of the subscriberwhen the cord is connected with the line.

78. In a telephonesystem, a substation and a central station and lineconnection between the same, a calling sig nal and a battery foroperating the same at the central station, said battery being normallyconnected with both sides of the line, the signal serving as medium ofconnection between the battery and one side of line, a calling'de- .viceat the substation for operating said calling signal} the line beingnormally open at the calling device of the substation, and a normally'open local circuit which closes in parallel with the line when a callis sent in and which holds the calling signal in operation untilrestored by the operator, an operator's connecting cord, and asupervisory signal under the control of the subscriber whenthe cord isconnected with the line.

79. In a telephone system, a substation and a central station andnormally open line connection between the same, a calling signalconsisting ofalamp arranged to light when a caliis sent in from thesubstation, 'arelay associated with said lamp. a suitable device at thesubstation for causing the operation of said culling signal. a batteryat the central station for supplying currcut in said lamp, said batterybeing normally connected with the line through said relay and lamp, anda local circuit which is closed when a call is sent in and whichaltordsa short circliit of comparatively low and unvc t: resistancethrough which the current from said battei y ilows for the purpose oflighting said lamp. an opcratous connecting cord, and a supervisorysignal under the control of the subscriber when the cord is connectedwith the line.

station and a complete metallic line conncc'tion lie'twccn the same, aspring jack and a plug and a cord circuit with a clearing-out signal, acomplete metallic line circuit which is opened to operate saidclearing-out signal, a callsame at the central station. a short-circuitconnection between the terminals 01' the line at the central station,said short-circuit connection being normally open, a local cir- 'cuitincluding the battery and relay and short-circuit'connection, and acalling device ut the substation for operating said main line aftera'call is sent in, an operator's connecting cord, and a supervisoryrelay under the control of the subscriber when the cord is connectedwith the line.

81. In a telephone system, a line circuit normally open at one station;a switcli or like circuit-changer,therefor at said station; a source ofcurrent, a relajv,,:\nd a signal receiving device all'at anotherstationyand anormally :through the contact points of said relay andcontrolled thereby; the said source, relay, and signal devicebcing in asection ofconductor forming part 01' botlrline and local circ nitspanoperator-s connecting cord and a supcrvisory signal under thecontrolofihe, subscriber when the cord is connected with the line. V

82. A telephone system comprising a substation and a central'stationwith line connection, a batter and alocal under-the control of thesubscriber when the cord is connected with the line.

circuit'conncctiou, the said relay being located in a con ductor formingpart of both-the line and local circuits, an operator's connecting cord,and a supervisory signal under the control of the subscriber when thccord is connected with the line. 7

84/111 a telephone system, the combination of a subscribcrs linc, atransmitter a line rclay, a li'nc signal operutcd by said relay, meansfor supplying current through the transmitter and line circuit forinitially encrgizing said relay. and a normally open local circuitassociai'ed with suidlinc signal, the coil and the normally separatedcontacts ot' s:iid rclay being includcd in'said local circuit. and therelay coil being alsolncludedin the line circuit in series with saidtransmitter, an operator's connecting cord, and a supervisory signalonly under the control of the subscriber when the cord is connected withthe line.

85. in a telephone system, thecombination of a subscribcr's liuc circuita local circuit -at.thecentral exchange, menus for supplying currentthrough said circuits,

80. In a telephone system, a substation and a central,

ing signal and 'a relay and a battery for-operating theopen associatedlocal circuit at said other station leading and a supervisory signal 83,In a telephone system, the combination of a sub the line terminals atthe and a local circuit including said battery relay and shortrelay andthereby closing said short-circuit connection so as to excludethe signalcurrent from thecircuit at the central station, a relay for closing thecura. line relay responsive to calls and adapted tor closing said localcircuit, the coil said relay being connected -andarranged to form partyof both line'an'd local circuits,

and a line lamp located in said local circuit, an operators connectingcord, and a supervisory signal under the conlow resistance connectionacross the terminals of the two limbs at the central station, and arelay for closing said connection, said connection when closed operatingto short-circuit the said substation apparatus, an operator'sconnectingcord, and a supervisory signal under the com froi of thesubscriber when the cord is connected with the line. v v

87. ln a telephone system, the combination of stations and lineconnection between the same, a calling device at. one or said stations,a calling signal and a battery at the other station, a normally openlocal circuit including said battery, said battery being normallyconnected with the line, and a relay, for closing said local circuit,the operation of said, calling device causing the current of said bat-.tery to'llrst flow over theline, and the energizationof the relaythen'operating to transfer the current to said local circuit. asubscriber's calling circuit for getting the atten tion of the operator,said circuit including a winding of said relay and both sides of theline in series.

' SS. in a telephone system, the combination of av substation and'acentral station, a line'clrcuit connecting said substation and saidcentral station, a calling device at said substation, a calling signaland a relay and a battery at the central station, a normally open bridgeof practically no resistance across the line at the central station, :1normally open local circuit including said battery and relay .andbridge, said battery being'normaily connected with the line; said'localcircuit when closed by the relay operating to. completely short-circuitthe said substation, so as t0 take battery curren't away from thesubstation and permit .the operator to answer a call without producingsounds in the receiverat said station, a subscriber's calling circuitfor getting theattentlon of the operator, said circuit including bothsides of the line in series. 1

so. in a telephone system, the combination of a substation and a centralstation-and suitable line connection between the same, a' calling deviceat said substation, a call-- ing'signal at the central station, a relayanda battery at said central station, a normally open local circuitincluding saidbattery and relay, said relay and said calling signalbeing responsive-to said calling. device, and the local circuit whenclosed by the relay operating to hold or look the calling signal inoperntlonuntil the call is answered by the'operator, a subscriber'scalling circuit for getting the attention of the operator, said circuitincluding a wind- .when the operator answers,

90. in a telephone system, a substation and. a central station and line'connection between the same, a calling signal and a battery foroperating the me nt the central station. said battery and signal beingnormally connected with the line, the signal serving as medium ofconnection between the battery and line, a calling device at the sulrstation for operating said c'alling signal, the line being normally openat. the substation, and a normally open local circuit which closes whena call is sent in and which holds the calling signal in operation untilrestored by the operator, a. subscribers calling circu'lt i'or gettingthe attention of the operator, said circuit including both sides of theline in series.

91. In a telephone system. a substation and a central station andnormally 'open' line connection between the same. a calling signal.consisting of a lamp arranged to light when rt call is sent in from thesubstation, a relay associated with said lamp, .1 suitable device at thesubsta- .tion i'or causing theoperation of said calling signal, a

battery at the central station for supplying current to said lamp,said'battery being norr allyconnected with the line through-said relayand lamp, and a local circuit which is closed when a call is sentln andwhich affords a short circuit of comparatively low and nnvarying'resistance through which the current from said battery flo'ws for thepurpose of lighting said lamp, a subscriber's calling circuit forgetting the attention of the operator, said circuit in-' cluding bothsides of the line in series.

92. In a telephone system, a substation and a. central "station and acomplete metallic line connection between the same, a spring jack and aplug and a cord circuit with a clearing-out signal, a complete metallicline circuit which is opened to operate said clearing-out signal, acalling signal and a relay and a batteryfor operating the same at thecentral station. a short-circuit connection be tween the terminals ofthe line at the central station, said short-circuit connection beingnormally open, a-localcircuit including the battery and relay andshort-circuit connection, and a calling device at the substation foroperat- -ing said relay and thereby closing said short-circuitconnection so as to exclude the signal current from the main.

line after a call is sent in, a subscriber-s callingcircuit for gettingthe attention of the operator, said circuit including' both sides of theline in series.

93. In a telephone system, a line circuit normally open at one station;a switch or like circuit-changer therefor at said station; a source ofcurrentfa'. relay, and a signal receiving device all at another station;and a normally open associated local circuit at said other stationleading through the contact points of said relay and controlled thereby;the said source, relay, and signal device being in circuits; asuhscribers calling circuit for getting the attention of the operator,said circuit including both sides or the line in series. 7 I

94. A telephone system comprising a substation and a central stationwith line connection, a battery and a local circuit at the centralstation, a relay for closing the current. of said battery through saidlocal circuit when a call is sent in, the batterybeing normallyconnected with one sideof theline through a winding ot'said relay, andthe relay winding'forming a part of both line and local cir cuits, acalling device at the substation for operating said relay, a visualcalling signal at the central station assoelated-with said'relay andoperate'd by said battery,.and a subscribers calling circuit for gettingthe attention of the operator, said circuit includingfboth sides of theline in series.

95. In a telephone system, the combination of a sub--' scrlbers line,a'hook switch for opening and closing the line circuit, a batterynormally connected with the line, a

line relay for operating the line signal, a normally open short-circuitconnection across the line terminals at the central station, saidshort-circuit connection being closed bythe energlzation of the linerelay when a call is sent in, and a local circuit including said batteryrelay. and shortcircuit connection, the said relay being located Ju aconductor forming part of'both the line and local circuits, a

subscribers calling circuit for getting the attention of the operator,said circuit including both sides of the line in series.

96. In a telephone system, the combination at a sub scribers line, aline relay, a line signal operated by said relay, means for supplyingcurrent through the line cira section of conductor forming part of-bothline and local 4 cuit for energizing said relay, and a; normallyopen-local :1 line relay responsive to calls and adapted for closingsaid localclrcuit, the coil of said relay eing connected and arranged toform part of both line an local circuits, and a line lamp located insaid local circuit, a subscrlbers calling circuit for getting theattention ofithe operator. saidclrcuit including both sides of the lineinsei-les.

98. A telephone system comprising a subscriber's line .with said lineand cord to furnish current for consisting of two metallic limbs,suitable substation apparatus, suitable central station apparatus, anormally open low resistance connection across the terminals of the 100.The combinationwith a telephone line and a con nection terminal therefornormally not in operative rela tion with said line, of a connecting plugand cord circuit adapted to cooperate with said line,, a supervisorysignal controlling magnet and a battery associated with said -cordcircuit, a switch at the subscriber's station, and

means controlled by the insertion of the plug into thejack for placingsaid jack in operative relationwith the line, whereby said signalcontrolling magnet is placed under the control'of the subscriber, anormally open low resistance connectlonbridged across the line at thecentral station, and means for closing said connection to short-circuitor shunt the-line when the subscriber calls, 1

'101. The combination with a telephone line, and a connection' terminalin the form of a spring jack normally not connecting plug, withsaid-line'and circuit to furnish talking current to rentactuated byplacing said jack normally open low resistance connection line at thecentral station, nection to short-circuit or scriber calls. I v

102. The combination with a telephone line and a connection terminal intheform of a spring jack.normally bridged across the and 'meansfo rclosing said con shunt the line when the sub not in operative relationwith said line, of a cord circuitsupervisory signaling apparatus as andconnecting plug, sociated with said circuit, a central source of currentassociated with said line and circuit to operate said supervisoryapparatus, and a relay adapted to be energized from in operativerelation with the line when said plug is mserted into said jack, anormally open low resistance connection bridged across the line at thecentral station, and means for closing said connection to short-circuitor shunt the line when the subscriber calls.

103. The combination with a, telephone line and a con nection terminalin the form of a spring jackfof a connect-- ing plug and a cord circuit,a central source of current for controlling the operative relation ofsaid jack with said line, a normally open low resistance connectionbridged across the line at the central station, and means for closingsaid connection to short-circuit or shunt the line when the subscribercalls.

104. In atelephone nection terminal in the form of a spring jacknormally not in operative relation with said line, a central source ofcurrent and supervisory signaling apparatus associated circuit, saidsource being adapted the operation of said apparatus and for talkingpurposes, and a relay actuated from'said source plug and cord circuittowhen said plug is inserted in said jack to place said signaling devicein inoperative relation with said line and said jack in operativerelation with said line, a normally open .low resistance connectionbridged across the line at the central station, and means for closingsaid connection to short-circuit or sham the line when thesubscriber-calls.

105. The combination with a telephone line having a limb extending tothe central station, of a line contact for said limbnormallydisconnected therefrom, a cord circuit and connecting plug,supervisory signaling apparatus connected with said circuit, a centralsource of current associated with said line and circuit to furnishcurrent for and circuit to furnish current for system, a metalliccircuit line, a con-.

ing or shuntingthe line talking purposes and for the operation of saidsupervisory apparatus and means for automatically connecting said linecontact with said limb when the lineisin use and for disconnecting thesame therefrom when'theline is not in use, a normally open lowresistance connection bridged across'the line at the central station,and means for clos- 'ing said connection to sllort-circuit or shunt theline when the subscriber calls.

106. The combination with a telephone line having a limb extending tothe central station, oi. asignaling device line, normally disconnectedtherefrom, connecting plug, supervisory signalinga apparatus associatedwith said cord circuit, current for talking purposes and for theoperation of said a central battery to furnish,

connection bridged across the line at the central station,

and means for'closing said shunt the line when the subscribercalls. H

107. The combination with a telephone line having a limb extending tothe central station, of a spring or moving part with which saidlimiconnects at the central otiice,

line contact for said limb, a cord cuit and connecting plug, a centralbatteryassociated with the said line circuit, supervisory signals alsoassociated with the circuit, said battery being adapted to furnishcurrent to the substations for talking purposes and for operating saidsupervisory signals, and a relay also cnergized to disconnect saidspying or part and to co'nnectit with thefline from said battery'adaptedfrom the signaling device contact when a connection is established withthe lineQla' connection to short-circuit or cir- I normally open lowresistance eonhection bridgedacross the line at the central station, andmeans for closing said con: nection to short-circuit or shunt the linewhen thesubscriber calls.

108. The combination with a'telephone line and a connoction terminalthcrefor normally not in operative rela-- tion witlrthe line, of aconnecting plug and cord circuit to x cooperate with said line, asupervisory signatcontrolling under the control of the subscriber, alocal circuit for short-circuitiug or shunting means controlled by theinsertion of theplug into the jack for placing s'aid jack in operativerelation with the line, whereby said signal controlling magnet iscontrol of the subscriber,

made with the line. i 110. The combination with a telephone line, and aconnection terminal in the form of a spring jack normally not inoperative relation with the line, of a cord circuit and a placedunder'the' a local circuit for short-circuit-- when the subscribercalls, and means for opening said local circuit when a connection is iconnecting plug, a central source of current associated with said lineand circuit to furnish talking r'-1rrent to the substations, and meansincluding said sou .e of current actuated by the insertion of said plugin the jack for placing said jack inoperative relation with said line, alocal circuit forshort-circuiting or shunting the line when thesubscriber calls, and means for openingsaid local circuit when aconnection is made with the line.

1 with the'line when said plug is inserted into said jack, a localcircuit for short-circuiting or shunting the line when the subscribercalls, and meansfor opening said local circuit when aconnection is madewith the line.

112. The combination with a telephone line and a con nection terminal inthe form of a spring jack, of a con necting plug and a. cord circuit, acentral source of current associated with said line and circuit tofurnish current for talking purposes, supervisory signal apparatusassociated-with the cord circuit and operated from said source ofcurrent, and a relay actuated from said source by the insertion of saidplug into and its withdrawal from said jack for controlllngthe operativerelation of said jack with the line, a local circuit forshort-circuitlng or shunting the line when the subscriber calls, andmeans for opening said local circuit when a'connection is made with theline.

1-13. In a telephone system," a metallic circuit line, a

connection terminal in the form of a spring jack normally not inoperative relation with said line, a connecting plug'and a cord circuit,a signaling device normally in operative relation with said line, acentral source of current and supervisory signaling apparatus associatedwith said line and cord circuit, said source being adapted to furnish,current for the operation of said apparatus and for talking purposes,and a relay actuated from said soul-cc when said plug is. inserted insaid jack to place said signaling device in inoperative relation withsaid lineand said jack in operative relation with said line, a localcircuit for short-circuiting or shunting the line when the subscribercalls, and means for opening said local circuit when a connection ismade with the line.

ll-l. The combination with a telephone line having a limb extending tothe central station, of a line contact for said limb normallydisconnected therefrom, a cord circuit and connecting plug, supervisorysignaling apparatus connected with said circuit, a central source ofcurrent assoelated with said line and circuit to furnish current for115, The combination with a telephone line having a limb extending tothe central station, of a signaling device normally connected with saidlimb, a line contact for said line normally disconnected therefronnncord circuit and connecting plug; supervisory signaling apparatus asso'ciated with said cord circuit, a central battery 'to furnish current fortalking purposes and for the operation of said apparatus, and a relayenergized from said battery adapted to disconnect said limb from saidsignaling dcviceand to connect the same with the line contact when aconnection is established with the line, a local circuit for shortcircuiting or shunting the,liue when the subscriber calls,

and means for opening said local circuit when a connection is made withthe line.

lid. The combination with a telephone line having a limb extending tothe central station, of a spring or mov ingpart with which said limbconnects at the central office. a signaling device connected with saidspring or part in it's normal position, a line contact for said limb, acord circuit and connecting plug, a central battery associated with thesaid line circuit, supervisory'signals also associated with the circuit,said battery being adapted to furnish current to the substations fortalking purposes and for operating said supervisory signals, and a relayalso energized from said battery, adapted to disconnect said spring orpart from the signaling device and to connect it with the line contactwhen a connection is established with the line, a local circuit forshort-circuiting or shunting'tho line when the subscriber calls, andmeans for opening said local circuit when a connection is made with theline.

117. The combination with a telephonedin'e and a connection terminaltherefor normally not' in operative relation with the line, of aconnecting plug and cord circuit to coiiperate with said line, asupervisory signal controlling magnet and a battery associated with saidcord circuit, a telephone transmitter and a switch at the subscriber'ssta tion, and means including a local circuit controlled by theinsertion of the plug into the jack for placing the jack in operativerelation with the line when the subscriber calls, whereby talkingcurrent from said battery is furnished to said transmitter and saidmagnet is placed under the control of the calling subscriber, asubscriber-s bell or ringer, a source of ringing current adapted to bebridged across the line to operate said bell or ringer, and a ringingcircuit including both sides of the line.

. 118. The combination with a telephone line and a connection terminaltherefor-normally not in operative rela tion with said line, of aconnecting plug and cord circuit adapted to coiiperate'with said line, asupervisory signal controlling magnet and a battery for energizing thesame nssociated'with' said cord circuit, aswitch at the subscriber's'station, and means controlled by the insertion of the plug into the jackfor placing said jack in operative relation with the line, whereby saidsignal controlling magnet and battery are placed under the control ofthe subscriber, a subscriber's hell or ringer, a source of ringingcurrent adapted to be bridged across the line to operate said hell I orringer, and a ringing circuit including both sldcs of the in operativerelation with the line, of a cord circuit and a connecting plug, acentral source of current associated with said line and circuit tofurnish talking current'to the substation, means independent of saidline, including said source of current, actuated by the insertion ofsaid plug in the jack, for placing said jack in operative relation withsaid line, when the operator answers a call, a subscriber's hell orringer, a source of ringing current adapted to be bridged across theline to operate said boil or ringer, and a ringing circuit includingboth sides of the line.

120. The combination with a telephone line and a con: nection terminalin the form of a spring jack normally not in operative relation withsaid line, of a cord circuit and connecting plug, supervisory signalingapparatus associated with said circuit, a central source of currentassociated with said line and circuit to operate said supervisoryapparatus, and a relay adapted to be energized from said source to placesaid jack in operative rehiiion with the line when said plug is insertedinto said jaclt. a subscribers hell or ringer, a source of ringingcurrent adapted to be bridged across the line to operate said hell orringer, and a ringing circuit including both sides of the line.

121. The combination with a telephone line and a conncction terminal inthe form of a spring jack, of a con necting plug and a cord circuit, acentral source of current associated with said line and circuit tofurnish current for talkingpurposes, supervisory signal apparatusassociated with the cord circuit and operated from said source ofcurrent. a relay actuated from said source by the insertion of said pluginto and its withdrawal from said jack. for

controlling the operative relation of said jack with. said line, alocul.circuit closed to keep said relay energized while the line is inuse for talking purposes, a subscriber's hell or ringer, a source ofringing current adapted to be bridged across the: line to operate saidhell or ringer and a ringing circuit including both sides of the line122. in a telephone system, a metallic circuit line, a connectionterminal in the form of a spring .jack normally 133. The combinationwitha telephone line having a .hmh extending to the central station, ofa spring or moving part with which said limb connects at the centralotiice.

a signaling device connected with said spring or part in -it s normalposition, a line contact for said limb, a cord circuit and connectingplug, a central battery associated with the said line circuit,supervisory signals also associated with the circuit, said batterybeingadapted to furnish current to the substations for talking purposesand for operating. said supervisory signals, and a relayalso energizedfrom said battery adapted to disconnect said spring or part from thesignaling device and to connect it adapted to be closed by the openingof said energizing circuit.

134. The combination with a telephone line and a spring jack therefornormally totally disconnected therefrom, of a connecting plug and cordcircuit to cooperate with said line, a supervisory signal controllingmagnet and a battery associated with said c'ord circuit, a telephonetransmitter and a switch at the Subscriber's station, means controlledby the insertion of the plug into the jack for placing the jack inconnection with the line, local circuit closed by the plug and jackwhile the line is in use for talking purposes, whereby talking currentis furnished to said transmitter and said magnet is placed under thecontrol of the subscriber, a' subscribers hell or ringer. and acondenser for stopping the dew of battery current through said hell orringer, together with provisions by which the supervision is independentof the ground between the subscriber's station and the central station.12-15; 'Ihe'combination with a telephone line and a spring jack therefornormally totally disconnected therefrom, of a connecting plug and cordcircuit adapted to cooperate with said jack. a supervisory-signalcontrolling magnet and a battery associated with said cord circuit, aswitch at the subscribers station, means controlled by the insert'ion oithe plus into the jack for placing said jack in connection with theline, whereby said signal controlling magnet is placed under the control01. the subscriber, a

subscriber's bell or ringer, and a condenser for stopping the llow ofbattery current through said hell or ringer, together with provisions bywhich the supervision is independent of the ground between thesubscriber's station and the central station.

136. The combination with a telephone line, and a conncction terminal inthe form of a spring jack normally not in operative relation with theline, of a cord circuit and a connecting plug, a central source ofcurrent associated with said line and circuit to furnish talking currentto the substations, and means including said source 01 current andactuated by the insertion of said plug in the jack for placiun said jackin operative relation with said line, said means comprising a localcircuit closed OW l cord strand while the line is in use for talkingpurposes, a subscribers boil or' ringer. and a condenser for stoppingthe ilow of battery current through said hell or ringer, together withprovisions by which the supervision is independent of the ground betweenthe subscriber's station and the cell,-

tra l station.

1557. The combination with a telephone line and a connection terminal inthe form of a spring jack normallynot .in operative relation with saidline. of a cord circuit and supervision. is independent of the groundbetween the subscriber's station and the central station.

138. The combination with a telephone line and .a consaid meansincluding a.

nection terminal in the form of a spring jack, of a connecting plug anda cord circuit. a central source of current as sociated with said lineand circuit to furnish current for talking purposes. supervisorysignalapparatus associated with the cord circuit and operated from saidsource of current. and a relay actuated from said source bythe-insertion of said plug into and its withdrawal from said jack forcontrollinw, the operative relation of said jack with said line. 21subscribers hell or ringer, and a condenser for stopping the How ofbattery current through said hell or ringer, together with provisions bywhich the supervision is independent of the ground between thesubscriber's sta tion and the central station. 139. In a telephonesystem. a metallic circuit line, a connection tenminalin the form ofa-spring jack normally not in operative relation with said line, aconnecting plug and a cord circuit, a line signaling device normally inoperative'relation withsaid line, a central source of-battery currentand supervisory signaling apparatus associated with said line and cordcircuit, said source being adapted to furnish current for the operation.of said apparatus and for talking purposes, and a relay actuated fromsaid source when said plug is inserted in said jack to place saidsignaling device in inoperative relation with said line and said'jack inoperative relation with said; line, a line signaling circuit excludingall winding of said relay, :1 subscriber's hell or ringer, and acondenser for stopping the flow of battery current'through said hell orringer, together with provisions by which the supervision is independentof the ground between the subscriber's station and the central station.H

H0. The combination with a telephone line having a limb extending to thecentral station, of a line contact for said limb normally disconnectedtherefrom, a cord circuit and connecting plug, supervisoryjsignalingapparatus connected with said circuit, a central source of currentassociated with said line and circuit to furnish current for talkingpurposes and for the operation of, said supervisory apparatus, and meansindependent of the line outside the central station for automaticallyconnecting said line contact with said limb when the line is in use andfor disconnecting the same therefrom when the line is not in use, asubscrihei"s hell or ringer, and a condenser for stopping the tlow ofbattery current ,through said hell or ringer, together with provisionsby which the supervision is independent of the ground between thesubscrihci"s station and the central station.

141. The combination with a limb extending to the central station, ofasignaling device normally connected with said limb, a line contact forsaid line normally disconnected thereform, a cord circuit and connectingplug, supervisory signaling apparatus associ' ated withsaid cordcircuit, a central battery to furnish current for talking purposes andfor the operation of said apparatus, and a relay energized from saidbattery adapted to disconnect said limb from said signaling device andto connect the same with the line contact when a con ncction isestablished with the line, a normally open local energizing circuit forsaid relay, closed when the operator answers a' call, a subscriber'shell or ringer, and a condenser for stopping the flow of battery currentthrough said hell or ringer, together with provisions by which thesupervision is independent of the ground between the subscriber'sstation and the central station.

142. The combination with a telephone line having a limb extending tothe central station, of a spring or movbig part with which said limbconnects at the central othce, a signaling device connected with saidspring or part in its normal position, a line contact for said limb, acord circuit and connecting plug, a central battery associated with thesaid line circuit, supervisory signals also associated with the circuit.said battery being adapted to furnish current to the substations fortalking purposes. and for operating said supervisory signals. and arelay also energized from said battery adapted to disconnect said springor moving part from the signaling device and to connect it with the linecontact when a connection is established with the line, the lineconnection with the battery excluding all winding of the said relay, asubtelephone line having a niitter .and connecting' plug,

srribers hell or ringer, and a condenser for stopping the tlow ofbattery current through said hell or ringer, to

gcther with provisions by which the supervision is 'indc-.

v pendent of the ground between the subscrihtrs station and the centralstation.

142%. lhe combination with a telephone line and a connection terminaltherefor normally not in operative relation with the line. of aconnecting plug and cord circuit to ,coiiperate withsaid line, asupervisoigv signal t'olillulling" magnet and a battery associated withsaid cord -circuit. a telephone transmitter and a switch at the.subscrihcfls 1d means controlled by the insertion ot-t.he plug ,mtotheack 'for placing the jack in operative relation with the line wherebytalking current is furnished to said trans and said magnet is placedunder the control ot. the subscriber. the supervision being absolutelyindependent of the ground between the subscriber's station and-thecentral statiom 144. The combination with a telephone line and'a connection terminal therefor normally not in operative relation. with saidline, of a connecting plug and cord circuit adapted to cooperate withsaid line, a supervisory signal controlling magnet and a battery forenergizing the same associated with said cord circuit, a switch at thesubscrihers station, and'meaus controlled by the insertion of the pluginto the.jack for placing said jack in operative relation with the line,whereby said signal controlling magnet and battery are, placed under thecontrol of the subscriber, the supervision being absolutely independentof the ground between the subscriber's station, and the central station.

145. The combination with a telephone line, and a connection terminal-inthe form of a spring jack normally not in operative relation with theline, of -a cord circuit and a connecting plug, a central source ofcurrent associated substations, and means including said source of,current actuated by the insertion of saidplug in the jack for placingsaid jack in operative relationwith said line, the

nection terminal in the form of a spring jack normally not in operativerelationwith said'line, of acord circuit supervisory signaling apparatusassociated with said circuit, central source of current associated withsaid line and circuit to operate said super- 'visory apparatus, and arelay adapted to be. energized from said source to place said jack inoperative relation with said line and circuit to furnish talking currentto thewith the line when said plug'is inserted intothe said jack,

the supervision being absolutely independent of the ground between thesubscriber's station and the central station.

147. The combination with a telephone line and a connection terminal inthe form of a spring jack, of a connecting plug and'a cord c'ircuit,' acentral source of current associated with said line'and circuit tofurnish current for talking purposes, supervisory signal apparatusassociated with the cord circuit and operated trom said sonrce'ot"relation with said line, a central source of current and.

supervisory signaling apparatus associated with said line and cordcircuit, said source being adapted to furnish current for the operationof said apparatus and for talking purposes, and a relay actuated fromsaid source when said plug is inserted in said jack to place saidsignaling device in inoperative relation with said'line. and said jackin operative relation with said line, the supervision being absolutelyindependent of the ground between the subscriber's station and'thecentral station.

14!). The combination with a telephone line-having a limb extendingtothe central station, of a line contact for said limb normallydisconnected therefrom, a cord circuit and connecting plug. supervisorysignaling apparatus connected with said circuit. a central source oicurrent associated with said line and'circuit to furnish current fortalking piil'poscs and for the' operation of said supervisory apparatus,and .means for auttnnatically connecting said line contact with saidlimb when the line is in use and for disconnecting the same thcrelromwhen the line is not in use, the supervision beingabsolutely independentof the round between the subscrilwrs station and the central station.

150. The combination with a telephone line having a limb extending tothe central station, of a. signaling device vnormally connected withsaid limb, a line contact for said line normally disconnected therefrom,a cord circuit: and connecting plug, supervisory signaling apparatusassociated with said cord circuit, a central battery to furnishestablished with the line, and anenergizing circuit i'orsaid signallingdevice. said relay provided with a windingcr cludcd' from the saidenergizing circuit, the'supervision being absolutely independent of theground between the snbscribens station and the central station.

151. The combination with a telephone line having a iimb extending tothecentral station, of a spring or moving part with which said limbconnects at-the central otlice, a

signaling device connected with said springor part in'its normalposition, a line contact for said limb, a cord circuit and connectingplug. a central battery associated with the said line circuit,supervisory signals also associated with the circuit, said batterybeingadapted to fnrnislrcurrent to the substationsfor talkingpurposesand for operating said supervisory signals, a relay also energized fromsaid battery, adapted to disconncctsaid spring or'part from thesignaling device and to connect it with the line contact when aconnection is established with-the line, and an energizing circuit forsaid signaling device, said -relay provided with awinding'excluded fromthe said energizing circuit, the supervision being absolutelyindependent of the ground between the subscriber's station and thecentralstation. Y I I I 152. In a telephone system, a subscriber's line,a line relay, a source of electric current, a normally open line ciriit'tor energizing said relay, and a normally open local circuitcontrolled by the said relay and including an 9111913? gizing coilthereof, whereby the said local circuit is substitnted for the said linecircuit when tlie'i'elay is energized, each circuit including. saidsource of current, said line circuitincluding both sides of the. line inseries.

153. ,In a telephone syste1n,-'a sub'scribers line, a'line. relay. :1source of electric current, a normally openline circuit for energizingsaid relay, and a normally open local circuit controlled by the saidrelay and including an ener gizing coil thereof, whereby the said localcircuit is substituted for the said line circuit when the relay isenergized,

each circuit including said source of current, said lin'e circuit beingprovided with-normally closed relay contacts for opening the same.-

154. In a telephone system, a ,subsccibefls line, a line relay, :1source of'electric currenta normally open line circuit for initiallyenergizing said relay overboth sides of the line, and a normally openlocal eircnit'controlled by the said relay and including an energizingcoilthel'eof, whereby the said local circuit is substituted for thesaidline circuit when the relay is energized, each circuit .in- 'cludingsaid source of current, and a subscriber's hook switch controlling thesaid line circuit atthe subscriber's station.

The combination of a telephone line, a substation substation: v

156. The combination of a plurality of subscriber's telephone lines, asubstation for each line, normally dis circuit or shuntthe line andthereby quiet the same at the connected jacks for said lines, metallicline signal and supervisory signal circuits between the. exchange andthe substations, metallic talking and ringing circuits between and plugsfor connecting lines together, and energizing circuits for said relaysincluding portions of the cord, service between lines and the operationsof all said instrumentalities being independent of the ground atsubstations.

157. The combination of'a substation, a normally open metallic telephonetalking circuit, a normally open metallic connecting said contacts ,withthe talking circuit when theoperator answers a call emanating from saidsubstation.

158. The combination of a subscrlbers telephone line, a jack orswitchboard terminal individual to said line and normally disconnectedtherefrom, a subscribers common battery transmitter and hookswitch, acommon battery adapted to supply current to the line for both talkingand signaling purposes, a line' signal relay, an energizing circuit forsaid line relay including said'battery and line and hook switch andtransmitter, a cut-off relay for automatic ally retiring the line signaland connecting the jack with the line when the operator answers a call,an operators connecting cord and plugs, an energizing circuit for saidcut-off relay including said battery and a portion of said connectingcord, a supervisory signal relay, an energizing circuit for saidsupervisory relay including the said transniitter and hook switch, bothsides of the line, normally disconnected contacts of the jack, thebattery/anda portion of the said cord, said battery permanently" bridgedbetween .the talking strands of the connecting cord and normally bridgedbetween the normally disconnected limbs of said line,a subscribers callbelLor signal, a ringing generator, an operators switch for bridgingsaid generator between the talking strands of the cord to operate thesaid call hell or signal, another subscribers line terminal adapt ed tobe connected with said first-mentioned line through the medium of saidcordand plugs, a complete metallic circuit for energizing said bell orsignal, another supervisory signal relay, and an energizing circuit forsaid last-mentioned supervisory relay, which energizing circuit isopened by said operators switch when the generator isused for operatingthe subscribers ca'll hell or signal.

Signed by me at Chicago, Cook county, Illinois, this 22nd day of October1901.

HENRY P. CLAUSEN.

Witnesses:

CHAS. C. BULKLEY,

HARRY. P, BAUMGARTNER.

